diff --git a/README.md b/README.md index cc6db6e..f5546cb 100644 --- a/README.md +++ b/README.md @@ -10,7 +10,7 @@ smart people at [Hashrocket](http://hashrocket.com/). For a steady stream of TILs from a variety of rocketeers, checkout [til.hashrocket.com](https://til.hashrocket.com/). -_617 TILs and counting..._ +_618 TILs and counting..._ --- @@ -233,6 +233,7 @@ _617 TILs and counting..._ - [Install The Latest Version Of Node With Nvm](javascript/install-the-latest-version-of-node-with-nvm.md) - [ISO-8601 Formatted Dates Are Interpreted As UTC](javascript/iso-8601-formatted-dates-are-interpreted-as-utc.md) - [Matching Multiple Values In A Switch Statement](javascript/matching-multiple-values-in-a-switch-statement.md) +- [New Dates Can Take Out Of Bounds Values](javascript/new-dates-can-take-out-of-bounds-values.md) - [Numbers Are Empty](javascript/numbers-are-empty.md) - [Object Initialization With Shorthand Property Names](javascript/object-initialization-with-shorthand-property-names.md) - [Random Cannot Be Seeded](javascript/random-cannot-be-seeded.md) diff --git a/javascript/new-dates-can-take-out-of-bounds-values.md b/javascript/new-dates-can-take-out-of-bounds-values.md new file mode 100644 index 0000000..32102c0 --- /dev/null +++ b/javascript/new-dates-can-take-out-of-bounds-values.md @@ -0,0 +1,36 @@ +# New Dates Can Take Out Of Bounds Values + +You can create a new date by feeding it arguments for _year_, _month_, and +_day_. + +```javascript +> new Date(2017, 11, 31) +Sun Dec 31 2017 00:00:00 GMT-0600 (CST) +``` + +What happens if we push the _day_ value out of bounds? + +```javascript +> new Date(2017, 11, 32) +Mon Jan 01 2018 00:00:00 GMT-0600 (CST) +``` + +It rolls over to the next month. + +Does the same happen when we push the _month_ value out of bounds? + +```javascript +> new Date(2017, 12, 31) +Wed Jan 31 2018 00:00:00 GMT-0600 (CST) +``` + +Yep. + +What about negative values? + +```javascript +> new Date(2018, -1, 31) +Sun Dec 31 2017 00:00:00 GMT-0600 (CST) +``` + +It rolls the month, and consequently the year, back.